Question: What is the bibliography of the  PhD advisor to Karl Herzfeld?
Paraphrase: What is the bibliography of the PhD guide to Karl Herzfeld?
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q84763 wdt:P184 ?X . ?X wdt:P800 ?answer}
Answer: fine-structure constant, Bohr-Sommerfeld atom model, Sommerfeld identity, Sommerfeld radiation condition, Sommerfeld–Kossel displacement law, Sommerfeld number, Orr–Sommerfeld equation, Lectures on Theoretical Physics, black body